Automatic mixing and discharging system for plural liquids



April 5, 1927. 1,623,476

H. E. HOFFMAN AUTOMATIC MIXING AND DISCHARGING` SYSTEM FOR PLURAL LIQUIDS Filed Oct. 27, 1924 INVENTOR HERBERT EI. HOFF MANl ATTORNEY Patented Apr. 5, '1927. l

HERBERT E. HOFFMAN, OF FROVXDFINCE, RHODE ESLAND, ASSIGNOR TO GENERAL v:ElXINGU'ISEEit COMPANY, GF PROVIDENCE, :RI-IODE XSLAND, A CORPORA'.I.ION 0F DELAWARE.

ATJ'EOILATIC MIXING AND DISCHARG-ING SYSTEM FOR PLURAL LIQIDS. -i

Application filed October 27, 1924. Serial No. 746,036.

This invention relates to improvements in automatic mixing and discharging systems for plural liquids. More particularly it relates to lire extinguishing apparatus whereby two liquids, adapted to react chemically upon each other to produce a. lire extinguishing agent', such as lire foam, are

stored in separate containers until needed,

and then released simultaneously through a common dischargey outlet. Heretotore it has been thought necessary to provide, in addition tothe separate containers, separate pipe lines thence to some form of double outlet, as for example a sprinkler head having two orifices, one for each liquid. Owing tothecorrosive properties of one ot the liquids most commonly used, non-corrodible pipe has been required from the container of this liquid to the discharge nozzle, or sprinkler head; and the latter required to vprovide Vfor double discharge, has also been specially treated, as by lining with lead, to avoid the ravages ofthe corrosive liquid.

The present invention is directed to provide apparatus which for the most part can be madefup from regular stock supplies of pipe andsprinkler heads. The invention is to eliminate the need for special anti-corrosion devices and the special sprinkler heads heretofore required to provide separate valves for the two liquids. rlhus it lessens at the start the installation cost; and, as will hereinafter appear, by withholding` the corrosive liquid from the distributing lines until actual discharge occurs, the maintenance cost is materially reduced.

The, apparatus of the invention includes the provision of separate containers for the liquids, one ot which Vis preferably interiorly lined with lead in the usual way, From each container` a siphon leads; and these ysiphons join in a common discharge pipe having an outlet through one or more single ordinary thermo-responsive sprinkler heads which may be ,of any one 'of many well known commercial types. The down or dischargeV legs of the siphons, vand `the, upper ends of the entrance legs therepii, are primed with some neutral and non-corrosive liquid, 4as for example, water. Upon the opening of the sprinkler head, this water runs out, pulling thetwo liquids after it, according to the siphonic principle. As they reach the common discharge pipe the' liquids physically mix, and they become discharged before the chemical reaction between them proceeds iar renough to establish any appreciable pressure. The ldischarge of the two liquids in mixed and reacting relation then continues until the level in each tank gets down to the `entrance opening of its disclosed.

In the accompanying drawing, Figure 1 is an eleva-tion showing, in section, a tank containing the two liquids in separate compartments, and, in face view uncut, the siphons andtheir common discharge; andFigure 2 is anelevation, in larger scale,'showing the details of the tank vent.

Referring to the drawing, the tank is divided by a partition 12 to form separate containers 14 and 16, one of which 14, has preferably a lead lining 15 in which the corrosive or y acid liquid, otherwise usually known commercially as the A solution, is stored. The other container 16,` holds the alkali or B solution.

' From each container a siphonextends, 18, 20, delivering below the tank linto a common discharge pipe 22 having a thermally-responsive valve 2a, such as an ordinary automatic sprinkler head. rlhe discharge leg 18 of the siphon 18 from the container holding the A solution preferably extends downward through the B solution. With this arrangement the use of non-corrodible pipe is necessary only for the entrance leg 18 that stands in the A solution. At the crest l i ready.v for use; and this prevents any great as illustrated. When thus primed, they Vplugs 26 are Screwed into place, .and the cover 28 of the tank Ais attached. a p The `cover is illustrated as being provided with a vent 30k having two check valves 32, 3.4, one opening for discharge from the tank and the other openable for intake to the 'l tank. v Thus is provided a slight resistance which is sufficient to retard or prevent air circulation while the apparatus is waiting .amount of evaporation, yet provides relief Ainflow or outiiow of air when caused by suiiii cient 'change of pressure due to changes of `temperature within the tank, and provides y for iniiow of airvrwhen the apparatus oper ates. y

' f j yThe koperation is extremely simple. lVhile,

v` 4standing ready the intake leg oteach siplion contains its own kind ot liquid; its discharge leg containsthe priniingliquid, e. g. water;

vfand the space above'liquid levels at the crest 'y contains air; Upon the sprinkler head openfing, thewater columns inthe discharge legs immediately start totiiow `down through the *commondischarge Vpipe and the sprinkler.

In i

Thisv fall starts the siphons Working.

veachfthe suction draws over the solution standing in its entrance leg, the small quantity 'of air at thettop not'being enough tov M prevent this; and thereafter the siplionic acti-on continues until the liquid level in each tank `reaches the entrance oit its siphon. By making the tanks of about equal capacity, an'd'inaking the liquids ot suitable dilution Vvi'for a full tank of each "to require a full tank ofithe other forits vcomplete chemical reacftion, the 'discharge tlow'otthe liquids may be 'at equal rates, thus conveniently producing 40' theniost effectivek format-ion ot foam Vtor tire extinguishingy purposes, without havingr any-'considerable over-plus ofv either vliquid kv5to flow alone at the end. Y

W'hile the valveselected for illustration,

`fory holding the apparatus ready and tor starting fitsA discharge, fis of the automatic type 'known as a sprinkler head, operating at 1a certain temperature, it is obvious that la valve opened automatically by some :other i means might be used, ora valve arrangedto *be opened lonly manuallyfAlso it will be Eunderstood that the apparatus .is applicable .wtoflargelta-nks andthatthesystem or' dis- 'tribution pipingv therefrom may be Vindeiinitely'long and ramiiied or cross connected,

without requiringinore than the customary single sprinklerted by a single pipe at each 'A outlet station, as in vordinary water systems.

. bof

" I' system tor plural liquids adapted to re-act I claim as my invention:

An lautomatic mixing r and discharging chemically upon each other comprising the combination, with separate containers for said liquids, of a siphon 'for discharging the` liquid oi' each container having their discharge legs preliminarily primed with liquid,

said siphons being connectedy in a common.

discharge' passage; and a single valve controlling the common passage adapted to be opened to silent-simultaneous discharge yot the plural liquids.

- 2. An vautomatic mixing and discharging vsystem tor plural liquids adapted to re-act' chemically upon each other comprising the combination, with separatey 'containers for saidliquids, of a Siphon for discharging the liquid of each container having their discharge legs preliminarily primed ywith liquid, said siphons being connected i-ii a common discharge passage; and thermo-re-y sponsive ymeans normally preventing dis-` charge but adapted at a predetermined temperature to permit simultaneous discharge of the plurallliquids.

3. An automatic mixing and discharging syste-ni for plural liquids adapted to react chemically upon eac-h other comprising the combination with separate vcontainers for said liquids. ot'a Siphon risingit'rom oiieot them and: descending through thevother of them; and another siphon inv said other container; the discharge legs ot both siphons being preliniinarily primed and connected to a common discharge passage; and a valved outlet from said passage whereby upon opening the discharges from the two containers occur together. y v v p 4. `An automatic mixing and discharging system for plural liquids comprising the .combination with separate containersv .tor said liquids ot a siplion tor each liquid arranged for simultaneous discharge ofboth;

means lfor opening the crest ot each Siphon,

`to permit ot the priming 0i' the discharge leg system for plural liquids comprising the combination ofv a covered holder'v having separate liquid containing coi-npartments; a top vent, and valves associated with said vent providing a slight resistance to inflow and to outflow ot gases; a siphonirom each com-V y partment having a common outlet providing vsimultaneous discharge of said liquids; and

means controlling said outlet. y n

Signed at'Providence, Rhode Islaiid,this` ninth day of October, 1924.

HERBERT HOFFMAN. 

